Bifurcation catheter assembly with distally mounted side balloon and methods

1. A catheter assembly, comprising:

(a) a main catheter branch comprising:

i. a catheter shaft, the catheter shaft having a distal end portion and defining an inflation lumen;

ii. a main balloon positioned at the distal end portion of the catheter shaft, the main balloon having a distal waist portion; the main balloon having a proximal end portion and a distal end portion; wherein the main balloon includes the distal waist portion at the distal end portion

iii. a main guidewire housing, the main guidewire housing defining a main guidewire lumen; and

iv. a side balloon assembly, the side balloon assembly including:

A. a side balloon; and

B. a side inflation member, the side inflation member having a proximal end portion connected in fluid communication with the distal end of the side balloon, and a distal end portion connected in fluid communication with the main balloon at a location distal of the side balloon, wherein the side inflation member does not include a proximal end segment that extends from the side balloon in a proximal direction.

2. The catheter assembly of claim 1 , further comprising a side catheter branch, the side catheter branch defining a branch guidewire lumen.

3. The catheter assembly of claim 2 , wherein the side catheter branch is operatively connected to the side balloon assembly.

4. The catheter assembly of claim 2 , wherein side catheter branch is aligned with a longitudinal axis of the side balloon.

5. The catheter assembly of claim 3 , wherein the side catheter branch is connected to the side balloon at a side balloon connection point.

6. The catheter assembly of claim 1 , wherein the side inflation member is secured to the main balloon at a distal bond, the distal bond including a connection between a bond tube member, the distal waist portion of the main balloon, and the distal end portion of the side inflation lumen.

7. The catheter assembly of claim 1 , wherein the side balloon assembly terminates at a location distal of a proximal waist portion of the main balloon.

8. The catheter assembly of claim 7 , wherein the side balloon assembly terminates at a location adjacent to a proximal side surface of the side balloon.

9. The catheter assembly of claim 1 , wherein the distal waist portion of the main balloon includes a tab member, the tab member being defined by at least one slit formed in the distal waist portion of the main balloon that extends longitudinally.

10. A stent delivery system, comprising:

(a) a stent, the stent having a distal open end, a proximal open end, and a side branch aperture, the side branch aperture defined in the stent at a location positioned between the distal and proximal open ends; and

(b) a first catheter branch, the first catheter branch comprising:

i. a catheter shaft, the catheter shaft having a distal end portion and defining an inflation lumen;

ii. a main balloon positioned at the distal end portion of the catheter shaft, the main balloon having a proximal end portion and a distal end portion, the main balloon extending within the stent from at least the proximal open end to the distal open end of the stent;

iii. a guidewire housing extending through the main balloon from the proximal end portion to the distal end portion, the guidewire housing defining a main guidewire lumen; and

iv. a side balloon assembly, the side balloon assembly including:

A. a side balloon having a proximal end and a distal end; and

B. a side inflation member, the side inflation member having a proximal end portion connected in fluid communication with the distal end of the side balloon, and a distal end portion connected in fluid communication with the main balloon at a location distal of the side balloon, the side balloon being positioned in axial and radial alignment with the side branch aperture of the stent, wherein the side inflation member does not include a proximal end segment that extends from the side balloon in a proximal direction.

11. The stent delivery system of claim 10 , further comprising a side catheter branch, the side catheter branch including a distal end portion and defining a branch guidewire lumen, the distal end portion of the side catheter branch extending into the stent through the proximal open end of the stent and extending out of the stent through the side branch aperture.

12. The stent delivery system of claim 11 , wherein the side catheter branch is operatively connected to the side balloon assembly.

13. The stent delivery system of claim 12 , wherein the side catheter branch is connected to the side balloon at a side balloon connection point.

14. The stent delivery system of claim 10 , wherein the connection between the distal end portion of the side inflation member and the main balloon is a distal bond positioned at the distal end portion of the main balloon.

15. The stent delivery system of claim 14 , wherein the distal bond includes a thermal bond between the side inflation member, the distal end portion of the main balloon, and a bond tube that extends over at least a portion of the distal end portion of the side inflation member and within at least a portion of the distal end portion of the main balloon.

16. The stent delivery system of claim 10 , wherein the main balloon includes a distal waist portion at the distal end portion of the main balloon, and the side inflation member is connected in fluid communication with the main balloon at the distal waist portion.